Movable yarn drier having infrared heaters and automatic controls therefor



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Jan. 23, 1968 J. NORTON ET AL MOVABLE YARN DRIER HAVING INFRARED HEATERS AND AUTOMATIC CONTROLS THEREFOR Filed April 8, 1966 MOVABLE YARN DRIER HAVING INFRARED HEATERS AND AUTOMATIC CONTROLS THEREFOR 3 Sheets-Sheet 2 Filed April 8, 1966 INVENTORS JOHN NORTON JAMES HENRY COOPER 5 Sheets-Sheet 3 INVENTORS TERS Jan. 23, 1968 NORTON ET AL MOVABLE YARN DRIER HAVING INFRARED HEA AND AUTOMATIC CONTROLS THEREFOR Filed April 8, 1966 JOHN NORTON JAMES HENRY COOPER United States Patent 11, 4 Claims. (Cl. 34-48) ABSTRAGCT UP THE DISCLOSURE Textile sizing equipment for materials such as yarn including a series of drying cylinders and a size bath movable toward and away from the cylinders so that a predrying unit may be operatively positioned between the size bath and the cylinders. The pre-drying apparatus has a'pair of opposed banks of heating elements and reflectors alternated in each bank with the heating elements of each bank opposite the reflectors of the other bank. The material to be pre-dried passes between the opposed banks. The heating elements may burn continuously with a moisture detector varying their heating intensity.

This invention concerns drying apparatus and in particular the pre-drying of sized yarns prior to their passage around the normally used drying cylinders of a sizing machine.

It is known that if yarns are sized and passed in a wet state over the drying cylinders of a sizing machine they tend to bunch and stick together as the size is drying and consequently with bulk yarns or yarns of low twist when they are separated prior to winding onto the warp beam it is possible that they will, during the separation thereof become damaged, by some of the fibers being pulled therefrom due to adherence to an adjacent yarn or yarns. The resultant yarns on the warp beam are therefore of poor quality and strength and thus difficulties are experienced in weaving the yarn into fabric.

It is also known to pre-dry the sized yarn by passing it between banks of infrared heaters, or the like, before it reaches the drying cylinders and while the yarns are sufficiently separated to prevent adherence to each other. The object of pre-drying is to provide a dry surface skin on the sized yarns so that as they pass over the drying cylinders they will not adhere to adjacent yarns while the final drying is taking place.

Generally the banks of heaters are arranged so that, in accordance with individual yarn diameter, and yarn sheet speed all or only some of the heaters are operative. Such an arrangement has the disadvantage that when some heaters are off heat distribution across the yarn sheet is uneven and consequently the possibility of insuliicient predrying of some yarns remains.

The object of the present invention is to provide a pre-drying arrangement in which the above outlined disadvantage is eliminated.

According to the present invention a pre-drying apparatus includes at least one bank of heating elements arranged to lie in spaced relationships to a material to be pie-dried, for example a sheet of sized yarn, there being associated with the heaters and the product to be dried a moisture content detector adapted to control the heat output or" the heaters whereby the heaters may be all operative continuously and the heat output can be varied to ensure substantially constant moisture content of the pre-dried product at the exit of the pre-drying apparatus.

The invention will be described further by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a schematic side elevation (with parts cut away) of one form of drying apparatus,

FIG. 2 is a plan view of the arrangement of FIG. 1,

FIG. 3 is a schematic layout drawing illustrating controls in block form,

FIG. 4 is a fragmentary view of a modification of the arrangement shown in FIGS. 1 and 2 and FIG. 5 is a detail view of part of a pre-drying apparatus shown in FIGS. 1 and 2.

In the following description reference Will be made to a pre'drying apparatus used in association with a warp sizing machine, but this does not restrict the invention to use in this manner only. Only those parts of the warp sizing machine relevant to this invention will be referred to.

As is known, a warp sizing machine includes a size bath 1i) through which a sheet 11 of warp yarns is passed to impregnate or coat the yarns with the size. Adjacent, and above the size bath are squeeze rollers 12 by which excess size may be removed from the yarn sheet 11 before it passes to the pre-drying apparatus of this invention.

The pre-drying apparatus is located between the size bath 10 and the first drying cylinder 13. The apparatus includes two banks of infrared heaters 14 and 14a (FIG. 5) there being one bank 14 above the warp sheet and one bank 14a below. The heaters extend across the whole width of the warp sheet 11. The banks 14 and 14a of heaters are arranged such that the heaters 14 alternate with reflectors 15 and the heaters 14a alternate with reflectors 15a. The reflectors 15 lie opposite the heaters 14a and the reflectors 15a opposite the heaters 14.

The heaters and reflectors are carried on frameworks 16 and 16a and these are connected together by chains 17, belts or the like. The chains 17 pass over pulleys 18 which are themselves mounted on cross ties 19 of a heater housing 20. The arrangement is such that the heaters can always be positioned to lie in planes parallel to a warp sheet 11 (or in the case of divided warp sheets, each parallel to one such sheet) and at any desired distance from such sheet and by connecting together the pulleys 18 by a link 21 adjustment of the heaters can be made from one position on the housing 29. The housing 20 is removably mounted on a chassis 22 which is provided at one end with a pair of wheels 23 and at its opposite end with a caster Wheel 24.

The heaters 14 and 14a are electrically connected in series to a voltage regulator 25 (FIG. 3), the voltage output of which is controlled by a pilot motor 26 which itself is operated by forward and reverse controls 27. The forward and reverse controls 27 are in series with a moisture content sensing device 28 which is adapted to emit a pulse when an indication of moisture content is given which is above or below a preset datum. The sensing device 23 is preferably arranged so that the pulses are emitted at a pre-set time interval if, of course, the moisture content of the warp sheet is greater or less than the preset datum. In addition, the length of the pulses may be varied so that an increase or reduction of output voltage from the voltage regulator 25 can be controlled in steps of, for example, 5 volts. The moisture content sensing device is operated by a sensing roller 29 which is in contact with the warp sheet 11 after the sheet leaves the infrared drying chamber. This arrangement is best seen in FIG. 3.

The size bath 10 is mounted on a wheeled carriage 30 the wheels 3011 of which (FIG. 5) run on rails 31 arranged to lie parallel to the longitudinal center line of the sizing machine. The beam creel 32 is similarly mounted.

In use, if the moisture content of the warp sheet is below that desired and set as the datum on the moisture content sensing device 28 '(FIG. 3), a pulse will be emitted to operate the control 27 which in turn energizes the pilot motor 26 to reduce the voltage output from the voltage regulator 25. This in turn will reduce the heat output from the banks to heaters 14 and 14a. If insuflicient reduction in heat effect is obtained by a 5 volt reduction, a further pulse will be emitted and a further reduction in voltage caused until such time as the voltage is of that value which will cause the required amount of pre-dryihg to be carried out on the warp sheet 11 before the warp reaches the sensing roller 29. If the moisture content of the yarn is too high then the pulses serve to operate the motor control 27 in the opposite sense to increase the voltage to the heaters 14 and 14a.

It is preferable to arrange for the heaters 14 and 14a to be movable from the warp sheet 11 so that in the event of a fault occurring in the apparatus or in the sizing machine the heaters 14 and 14:: can be moved away from the warp sheet to such an extent that they do not serve to over-dry the warp and in these circumstances, when the heaters 14 and 14a are moved, the voltage would be reduced to a minimum or completely switched off.

It is also desirable to be able to remove the pre-drying equipment completely, when, for example, drying high twist warp since normally pro-drying is not required for such yarns and if the pre-drying apparatus is not removable an excessive length of yarn exists between the squeeze rollers 12 and the first drying cylinder 13. It is for this reason, and to make the sizing machine universally acceptable that the pre-dryer, size bath carriage and creel are mounted on Wheels. In the arrangement being described the pre-dryer is moved out from its position adjacent the size bath and is then turned and wheeled away, the size bath carriage and creel then being moved to a position such that the size bath carriage occupies the space taken by the pre-dryer. The pre-dryer can of course be replaced whenever desired. In some instances the pre-dryer would not be movable and in others, as shown in FIG. 4, it would be mounted on rails 33, for movement to a position adjacent the sizing machine but clear of the warp sheet 11.

The invention is not restricted to the above details. For example, the infrared heaters could be replaced by infrared lamps or other heating means, and if desired a switch may be provided on the main motor of the sizing machine, which is effective to reduce the voltage to the,

heaters to a safe minimum when the speed of the warp sheet is below a pre-set creep speed.

What is claimed is:

1. A pre-drying apparatus for material to be pre-dried such as a sheet of sized yarn, comprising at least a pair of opposed banks of heating elements and reflectors adapted to lie in spaced relationships to said material the heating elements of one bank located opposite the reflectors of the other bank, the heating elements and reflectors of each bank alternating in each bank, and means associated with said heating elements for sensing the moisture content and varying the heat output of the heating elements with the heating elements all operative continuously and the heat output varied to ensure substantially constant moisture content of the pre-dried product at the exit of the pre-drying apparatus.

2. A sizing assembly for material such as a sheet of yarn, comprising a series of drying cylinders, a size bath, means mounting said size bath for movement between positions towards and away from said series of drying cylinders with said size bath operatively positioned for passing said material to said series of drying cylinders in both of said positions, a pre-dlying apparatus having a wheeled chassis for movement of the pre-drying apparatus between a position operatively disassociated with said size bath and said series of drying cylinders and an operatively associated position intermediate said size bath and said series of drying cylinders when said size bath is positioned away from said series of cylinders for the passage of said material from said size bath to said pre-drying apparatus and then to said series of drying cylinders.

3. A sizing machine according to claim 2 in which said pre-drying apparatus comprises at least one bank of elements for heating said material, and means for detecting the moisture content of said material and regulating the heat output of said heating elements responsive to said moisture content.

4. A sizing machine according to claim 3 and at least an opposed pair of said banks of heating elements, each bank having reflectors alternating with the heating elements, the heating elements and reflectors of each bank adapted to lie in spaced relationships to opposite sides of said material, the heating elements of one bank located opposite the reflectors of the other bank, and means associated with said heating elements for sensing the moisture content of the material and varying the heat output of the heating elements to assure substantially constant moisture content of the material at the exit of the machine.

References Cited FREDERICK L. MATTESON, JR., Primary Examiner. A. D. HERRMANN, Assistant Examiner. 

